1. Field of the Invention
This invention relates to a printing apparatus which converts a control code of printing information according to any of a plurality of emulation modes and prints characters according to the converted code.
2. Description of the Related Art
Various printing apparatuses are known in which printing information including at least a control code and character codes are entered, the control code is converted by an emulation mode compatible with the control code, and characters corresponding to the character codes are printed according to the converted control code.
In such printing apparatuses, a plural number of emulation modes and judgment data respectively corresponding to the modes, which data being for determining whether or not the printing information control codes are compatible with the emulation modes, are stored in a ROM (read-only memory) in a microcomputer incorporated in the printing apparatus. The emulation mode is selected to be compatible with the control code detected from the printing information and printing is performed according to the character codes of printing information based on the selected emulation mode.
Recently many kinds of emulation modes have come to be used with such printing apparatuses. Some of such printing apparatuses are structured to use a detachable ROM cartridge storing new emulation modes which are not originally provided in the printing apparatus.
Such printing apparatuses, however, are structured to print all the printing information in the emulation mode stored in the ROM cartridge irrespective of the control code once the ROM cartridge is inserted or an instruction is given through an operation panel after inserting the ROM cartridge. Therefore, in the case where the printing information requires both the emulation mode built into the printing apparatus and the emulation mode contained in the cartridge, a cumbersome operation is required involving inserting and removing the cartridge or requiring further operations on the operation panel.
Although many kinds of emulation modes and corresponding judgment data can be stored in advance in a built-in ROM in the printing apparatus, erroneous functioning can occur with an increase in the number of emulation modes. Namely, if the number of emulation modes is increased, in some cases the corresponding judgment data are very similar to each other. In that case, a certain kind of control code could be judged as being of similar judgment data and an emulation mode could be selected which does not correctly correspond to the control code.